/Engine/Source/Editor/AIGraph/Public/SGraphNodeAI.h
Handle mouse down on the node
[FReply](API\Runtime\SlateCore\Input\FReply) OnMouseDown ( const [FGeometry](API\Runtime\SlateCore\Layout\FGeometry) & SenderGeometry, const [FPointerEvent](API\Runtime\SlateCore\Input\FPointerEvent) & MouseEvent )